Map Projections

1 Set Up The Map

This part is admittedly a little complicated, mostly because I added options to get the map to look exactly the way that I wanted.

It’s not necessary to understand the code here. But I learned a lot from: https://plotly.com/r/#maps.

library(plotly)

# a very basic map could be created with: 

library(plotly)

plot_geo()

mymap <- plot_geo() %>%
  layout(title = "Demonstration Map", 
         geo = list(showland = TRUE,  
                    landcolor = toRGB("grey"),
                    showcountries = TRUE,
                    showocean=FALSE, 
                    oceancolor="LightBlue",
                    lataxis = list(showgrid = TRUE,
                                   gridcolor = toRGB("black")),
                    lonaxis = list(showgrid = TRUE,
                                   gridcolor = toRGB("black")))) 

2 Map Projections

2.1 Globe

mymap %>% 
  layout(geo = list(projection = list(type = 'orthographic')))

2.2 Mercator

Perpendicular latitude and longitude. Can be helpful in some kinds of navigation, but areas are distorted, especially as one approaches the poles.

mymap %>% 
  layout(geo=list(projection = list(type = 'mercator')))

2.3 Mollweide

An equal area projection.

mymap %>% 
  layout(geo=list(projection = list(type = 'mollweide')))

2.4 Robinson

An attempt to compromise between equal areas and a natural looking map.

mymap %>% 
  layout(geo=list(projection = list(type = 'robinson')))